OK. Now I see. The goal of 25-27 in summer and 22-24 in winter is quite realistic.
Some things that are really right about your truck:
The GV overdrive: Good gearing on demand.
Right sized tires: OEM-size tires are optimum for MPG
. Bigger diameter gets worse mileage because of the higher rotational moment of inertia and rolling resistance. Smaller tires make the engine rev up too much. The boys at the factory arenít complete fools. Ask me how I know this. Buying and trying a lot of tires, thatís how. Maybe a good idea is a set of winter tires and a set of summer tirees. Gnarly lugs for Michigan snow. Road pattern tires for warmer weather. My OEM-type firebombs have been a good all-around compromise.
Stuff I would recommend:
A stick shift is a solid 2 MPG
there for the taking. I have always been amazed how guys who will take on the complex problem of engine swaps are intimidated by an auto-to-manual transmission swap.
I think you are over-injected. Try driving to hold 600 degrees. If you canít do it (give yourself a couple weeks to get the knack) you are over-injected. I routinely run 500 EGT
, 2-3 psi
boost, and 1700 RPM @ 70 MPH. EGT
is a function of fuel burn. Less fuel burn (better MPG
) means lower EGT
. I would not mess with the turbo til you get EGTs
Given you have a 4x4
, I donít think a air dam is in order. I lowered my 4x2
4 inches in the front and 6 inches in the rear and my air dam is on the ragged edge of being too big. I donít think a 4x4
can be lowered without fab work that would make Jesse James (the bike builder) flinch. On a 4x4
it would look like the mainsail on Old Ironsides, and add more frontal area than the reduction in coefficient of drag it will make. Maybe a belly pan (another thread is going on this subject) might be a better idea for a 4x4
Some sort of bed cover is in order if you want to get to the mid-20s on a regular basis. For me a hard tonneau added 1.5 MPG
and my lewd, crude fastback added another 1.5. Hopefully, you can make something nicer than I did.
Compared to a Dodge or Chevy, the Ford is definitely heavier. There is a price to be paid for that sturdy construction and it is weight. But fuel is cheaper than repairs to cheesy trucks, IMO
I would not mess with auxiliary fuel (CNG, propane) until I got the No. 2 where you want it. I donít know about MI, but here on the frozen steppes of central Indiana, propane is more expensive than No.2 on a $/MMBTU basis. Before doing propane or CNG, take a long hard look at how much advance you are running. Propane (once blowtorched into ignition) has a very fast flame front and has been known to put windows in crankcases.
Something very cheap to do is adjust the nut behind the steering wheel (the driver). Read Beating the EPA - The Whys and How to Hypermile - CleanMPG Forums
This guy is the guru of high MPG
drivers. He does things that only the truly insane would do and his site has a load of politics I donít care for, but he has the goods. He has been verified as squeezing over 100 MPG
out of a first-generation Honda Insight and 47 MPG
out of a gas Ranger pickup on public roads, and does it on a routine basis. Most of the link is written from the standpoint of a hybrid, but read it and find the stuff you can (will) do and use it and discard the rest. The driver matters a lot. In Michigan I would not recommend driving real slow. People there might shoot you. Here in Indiana theyíd just throw a chair at you.
For me, my testing season is mid-May to mid-September. No doubt later for you, but that gives you time to make your mods and practice any new driving techniques you can do before you try a real test.
Send me a PM with an e-mail address and Iíll send some .jpgs of my fastback bed fairing.